The invention relates to a valve train device.
A valve train device for internal combustion engines, comprising an axially movable cam element on which a shift gate is provided, into which gate a shift element is introduced in order to convert a rotational movement of the cam element into an axial movement of the cam element, is already known from DE 196 11 641 C1.
The object of the invention is in particular to provide a compact valve train device.
A valve train device, in particular for an internal combustion engine, is proposed, comprising a support element and at least one cam element which can be moved axially relative to the support element, which cam element has at least one multitrack cam, the device also comprising a switch unit for axially moving the at least one cam element, which unit comprises at least one displacer that is intended to be at least operatively inserted between the support element and the cam element in order to axially move the at least one cam element. A shift gate can therefore be omitted, and the axial installation space required for the cam element can be reduced. A compact valve train device can thus be provided. “The displacer is intended to be at least operatively inserted between the support element and the cam element in order to axially move the at least one cam element” should be understood in this context to mean that the displacer is incorporated in a functional chain between the support element and the cam element and is supported by the support element such that the cam element is moved axially. In particular, the displacer can be inserted directly between the support element and the cam element and can directly displace the cam element in the axial direction. Alternatively, the displacer can be inserted between the support element and a further element, for example, and can displace the further element, the cam element then being axially moved by the further element.
Moreover, it is proposed that the support element should be fixed to a housing. As a result, the cam element can be particularly well supported while being axially moved.
It is also proposed that the displacer should be radially movable relative to the at least one cam element. This makes it possible to achieve a motion for operatively inserting the displacer between the support element and the cam element which is shorter than a path of movement of the cam element. Therefore, this makes it possible to achieve particularly rapid changeover between two switch positions which are associated with different axial positions of the cam element.
Furthermore, it is proposed that the displacer should have an inclined surface for insertion between the cam element and the support element. A displacement movement can thus be initiated substantially smoothly and a load on the valve train device can be reduced. In principle, the displacer can also have a straight surface, and the cam element, or a component connected to the cam element, can have the inclined surface.
It is additionally proposed that the inclined surface should be provided for coming into contact with the cam element and axially moving the cam element when operatively inserted between the support element and the cam element. A displacement movement can thus be initiated substantially smoothly and a load on the valve train device can be reduced.
It is also proposed that the switch unit should comprise a housing on which the displacer is substantially mounted. A particularly compact valve train device can thus be achieved. “The displacer is substantially mounted on the housing” should be understood in this context to mean that when the displacer is not operatively inserted between the support element and the cam element, at least 60 percent, advantageously at least 80 percent, and particularly preferably the entirety of the displacer is accommodated in the housing.
It is further proposed that the switch unit should have a further displacer that is intended to be inserted at least operatively between the support element and the cam element in order to axially move the cam element in a direction counter to the axial movement caused by the displacer. This thus makes it possible to achieve rapid changeover between two switch positions which are associated with different axial positions of the cam element. In principle, the displacer and the further displacer can be coupled by a rocker to avoid both displacers being operatively inserted at the same time. Alternatively, the displacers can also be uncoupled.
It is also proposed that the displacer should form an axial bearing for the cam element. An additional axial bearing for the camshaft can thereby be omitted, and a compact valve train device can be achieved. The displacer can form the axial bearing for the cam element entirely, or can form the axial bearing together with further components.
Moreover, it is proposed that the support element should form a radial bearing for the cam element. An additional radial bearing for the camshaft can thereby be omitted, and a compact valve train device can be achieved. The support element can form the radial bearing for the cam element entirely, or form the radial bearing together with further components.
The invention also relates to an internal combustion engine comprising a valve train device having at least one support element and at least one cam element which can be moved axially relative to the support element, which cam element has at least one multitrack cam, the device also having a switch unit for axially moving the at least one cam element, which unit comprises at least one displacer that is intended to be at least operatively inserted between the support element and the cam element in order to axially move the at least one cam element.
Further advantages are indicated in the following description of the drawings. The drawings show an embodiment of the invention. The drawings, the description of the drawings and the claims contain many features in combination. A person skilled in the art will advantageously also consider the features individually and combine them to form meaningful further combinations.